If both pronouns begin with the letter I the first one is changed to se

Le lo/les lo

become:

se lo

Le los/les los

become:

se los

Le la/les la

become:

se la

Le las/les las

become:

se las

Position

-In an affirmative statement with one verb the object pronouns will immediately precede the conjugated verb. Examples:

Juan me lo dio.

Yo se la regale.

-In a negative sentence with one verb the object pronouns are placed between the word no( or other term of negation) and the conjugated verb. Examples:

Juan no me lo dio
Yo no se la regale

- In a affirmative statement ,negative sentence or question wit htwo verbs( first verb is conjugated and second one in the infinitive form) there are two options:

Place object pronouns directly before the first verb

Examples: yo te lo wuiero contar. Yo no se los voy a comprar.

Attach the object pronouns directly to the second verb.

Examples: yo quiero contartelo. Yo no voy a comprarselos

Notes:

Redundancy

Even though the principal purpose of any pronoun is to replace a noun. Often it is clearer or more emphatic to use both the pronoun and a + the (pro) noun. This is done primarily with the indirect pronoun and more frequently with some verbs (see the list). The indirect object is usually in the third person.